The present invention relates to a semiconductor device using insulated gate bipolar transistors (hereinafter referred to as IGBTs) and to a plasma display driving semiconductor integrated circuit device using the IGBT semiconductor device.
An electrostatic breakdown of a semiconductor integrated circuit is caused by localized heating and electric field concentrations that occur when a discharge current from an electrostatic discharge (ESD) flows through the semiconductor device. With semiconductor devices being increasingly miniaturized in a higher density as their fabrication technology advances, the semiconductor devices in recent years tend to have a reduced capability to withstand ESD, making a problem of how to deal with the ESD an important issue. In high voltage power ICs using a SOI substrate, in particular, its structure in which an oxide layer (insulating film) with a low thermal conductivity surrounds the device causes a temperature increase from heating to be greater than when the device is formed on a Si substrate, giving rise to a possibility of having to take special considerations for the degraded ESD withstand capability.
One of conventional measures that have been taken against the ESD in semiconductor integrated circuits involves putting an ESD protective circuit between a high-voltage supply wire and a ground wire in parallel with a circuit being protected, to discharge ESD surges applied to external terminals. This method generally uses a diode or MOS transistor as a standard protective circuit device.